Ok, say an average person needs 2000 Calories per day
thats 8.38 MegaJoules (MJ)/day
(1 Calorie = 1000 calories = 4.19 KJ)
The total radiation that the earth recieves form the sun is
about 1KW/m^2 (in near earth orbit)
A watt is a Joule/sec, and there are 86,400 seconds in a day
that works out to 86.4MJ/day (note, the surface of the US
according to http://www.rt66.com/rbahm/GJANN30.GIF
gets about 20 MJ/m^2/day, but I am going for the HIGHEST number)
The area of the earth (including water) is about 500*10^12 m^2 which means we get 43.2 *10^15 MJ/day (should I divide by 2 since on average we get light for 1/2 a day?)
If ALL the suns energy was converted at 100% percent efficiancy into food, I get 5.16*10^15 people
This is ignoring oxygen and other essentials, and ignoring nuclear/geothermal energy, but it may be a useful upper bound.
** Beeblebrox ** I’m glad we could get that straight. I guess the only way to figure it out will be to fill this mother up. Hmmmmm…A global Manhattan…I think I like that idea alot!
I think after you build 100 of them, they all launch into space and you have to start over with a new city. Or maybe they changed that for SimCity 3000. Which I hate 'cause you can’t build hydroelectric power plants any more. Bleah.
So far, all the doomsayers have been proved wrong. 100% wrong. Note, this is not to say there aren’t serious ecological concerns. But unproven hysterics tend to lead eventually to disinterest, if not outright hostility.
The known universe should provide adequate space for us to grow in the forseeable future. Asking what the carrying capacity of the earth is in some ways irrelevant. That’s where our destiny lays- up, or out, depending on how you look at it.
I’d like to bring up waste removal/landfill capacity’s impact on this GD.
I remember reading something a while back which stated that landfill capacity would not be an issue in the future… that food production would be the determining factor.
I wish I could remember more specifics on the article. Anyway, is this true?
I know the Earth would have more than enough space to hold it, but at what point would our waste start to screw the environment? Sea Sorbust:
60 million is approximately the population of California and Texas put together (if you count all the aliens). Clearly there are more people in world than that currently. Jeez.
I just figured it out. Sea Sorbust read the O.P. and thought to himself “hmmmmm.” Being the type attracted to small shiny objects, he spotted a nearby cellophane-covered fortune cookie left over from his Mongolian Beef. Glittery plastic with panda bears. After eating said cookie, he reads this:
lucky numbers: 60 00 01 80
If we squish the numbers together and round off we get 60,000,000. He posts this number and goes back to watching “Dragonball Z”. After his answer is scoffed at, he looks at his “source” and reads:
which he then posts as an explanation. After this is scoffed at, Sea Sorbust recalls the episode of “Dragonball Z” he just watched and realizes that the limited population can protect the world from asteroids and possess technology useful for kicking ass. He then posts his new knowledge.
Acco40, it all depends on what type of waste we are producing and the amount of space available to build a landfill. Organic wastes can be composted to near nothing. Plastics and metals obviously can’t. In addition, if a landfill is run correctly, it should have almost no environmental impact because of its isolation (they are supposed to “seal” the ground before they build one to prevent groundwater seepage). I believe food supply and overcrowding would be the two major factors in determining maximum population.
-Beeblebrox
“Don’t tell me about the future,” said Ford. “I’ve been all over the future. Spend half my time there. It’s the same as anywhere else. Anywhen else. Whatever. Just the same old stuff in faster cars and smellier air.”
Don’t forget that carrying capacity is dependent on how long you want the population sustained (I’m assuming people here are interested in a sustainable population level, not just the maximum we could reach for a moment (geologically speaking) and then have them all die.)
We may be able to support a vast number of people. The largest number I’ve ever seen is 100 billion, in the popular press, with no supporting math, but I doubt we could support 100 billion people for very long. How long could we support 100 billion people? A couple centuries? Decades?
If we’re interested in supporting the population for a longer period of time (hopefully at least thousands of years), the number’s going to be smaller.
Also, a some people have written as if space is the problem - it isn’t. There’s plenty of room, but people also need food, fresh water, and in a modern society, innumerable manufactured goods. Sure you could fit 20 billion people into Montana, but does anyone here actually believe that Montana has enough water for 20 billion people? Produces enough food? Builds enough GI Joes with the kung-fu grip for the kids of all 20 billion people?
Even if we keep producing more food,clothing then their is still competition for housing etc.
Considering the effect of all the pollution and that birth rates fall as countries develop i suspect the world population will actually fall at some point.
Their is a natural limit… when we run out of resources.
